289 lines
8.2 KiB
C
289 lines
8.2 KiB
C
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2005-2009 Cavium Networks
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/msi.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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#include <asm/octeon/octeon.h>
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#include <asm/octeon/cvmx-npi-defs.h>
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#include <asm/octeon/cvmx-pci-defs.h>
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#include <asm/octeon/cvmx-npei-defs.h>
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#include <asm/octeon/cvmx-pexp-defs.h>
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#include <asm/octeon/pci-octeon.h>
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/*
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* Each bit in msi_free_irq_bitmask represents a MSI interrupt that is
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* in use.
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*/
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static uint64_t msi_free_irq_bitmask;
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/*
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* Each bit in msi_multiple_irq_bitmask tells that the device using
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* this bit in msi_free_irq_bitmask is also using the next bit. This
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* is used so we can disable all of the MSI interrupts when a device
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* uses multiple.
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*/
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static uint64_t msi_multiple_irq_bitmask;
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/*
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* This lock controls updates to msi_free_irq_bitmask and
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* msi_multiple_irq_bitmask.
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*/
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static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
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/**
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* Called when a driver request MSI interrupts instead of the
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* legacy INT A-D. This routine will allocate multiple interrupts
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* for MSI devices that support them. A device can override this by
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* programming the MSI control bits [6:4] before calling
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* pci_enable_msi().
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*
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* @dev: Device requesting MSI interrupts
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* @desc: MSI descriptor
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*
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* Returns 0 on success.
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*/
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int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
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{
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struct msi_msg msg;
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uint16_t control;
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int configured_private_bits;
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int request_private_bits;
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int irq;
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int irq_step;
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uint64_t search_mask;
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/*
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* Read the MSI config to figure out how many IRQs this device
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* wants. Most devices only want 1, which will give
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* configured_private_bits and request_private_bits equal 0.
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*/
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pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
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&control);
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/*
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* If the number of private bits has been configured then use
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* that value instead of the requested number. This gives the
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* driver the chance to override the number of interrupts
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* before calling pci_enable_msi().
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*/
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configured_private_bits = (control & PCI_MSI_FLAGS_QSIZE) >> 4;
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if (configured_private_bits == 0) {
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/* Nothing is configured, so use the hardware requested size */
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request_private_bits = (control & PCI_MSI_FLAGS_QMASK) >> 1;
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} else {
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/*
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* Use the number of configured bits, assuming the
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* driver wanted to override the hardware request
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* value.
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*/
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request_private_bits = configured_private_bits;
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}
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/*
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* The PCI 2.3 spec mandates that there are at most 32
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* interrupts. If this device asks for more, only give it one.
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*/
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if (request_private_bits > 5)
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request_private_bits = 0;
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try_only_one:
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/*
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* The IRQs have to be aligned on a power of two based on the
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* number being requested.
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*/
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irq_step = 1 << request_private_bits;
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/* Mask with one bit for each IRQ */
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search_mask = (1 << irq_step) - 1;
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/*
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* We're going to search msi_free_irq_bitmask_lock for zero
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* bits. This represents an MSI interrupt number that isn't in
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* use.
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*/
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spin_lock(&msi_free_irq_bitmask_lock);
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for (irq = 0; irq < 64; irq += irq_step) {
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if ((msi_free_irq_bitmask & (search_mask << irq)) == 0) {
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msi_free_irq_bitmask |= search_mask << irq;
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msi_multiple_irq_bitmask |= (search_mask >> 1) << irq;
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break;
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}
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}
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spin_unlock(&msi_free_irq_bitmask_lock);
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/* Make sure the search for available interrupts didn't fail */
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if (irq >= 64) {
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if (request_private_bits) {
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pr_err("arch_setup_msi_irq: Unable to find %d free "
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"interrupts, trying just one",
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1 << request_private_bits);
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request_private_bits = 0;
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goto try_only_one;
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} else
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panic("arch_setup_msi_irq: Unable to find a free MSI "
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"interrupt");
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}
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/* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */
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irq += OCTEON_IRQ_MSI_BIT0;
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switch (octeon_dma_bar_type) {
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case OCTEON_DMA_BAR_TYPE_SMALL:
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/* When not using big bar, Bar 0 is based at 128MB */
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msg.address_lo =
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((128ul << 20) + CVMX_PCI_MSI_RCV) & 0xffffffff;
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msg.address_hi = ((128ul << 20) + CVMX_PCI_MSI_RCV) >> 32;
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case OCTEON_DMA_BAR_TYPE_BIG:
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/* When using big bar, Bar 0 is based at 0 */
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msg.address_lo = (0 + CVMX_PCI_MSI_RCV) & 0xffffffff;
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msg.address_hi = (0 + CVMX_PCI_MSI_RCV) >> 32;
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break;
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case OCTEON_DMA_BAR_TYPE_PCIE:
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/* When using PCIe, Bar 0 is based at 0 */
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/* FIXME CVMX_NPEI_MSI_RCV* other than 0? */
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msg.address_lo = (0 + CVMX_NPEI_PCIE_MSI_RCV) & 0xffffffff;
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msg.address_hi = (0 + CVMX_NPEI_PCIE_MSI_RCV) >> 32;
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break;
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default:
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panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type\n");
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}
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msg.data = irq - OCTEON_IRQ_MSI_BIT0;
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/* Update the number of IRQs the device has available to it */
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control &= ~PCI_MSI_FLAGS_QSIZE;
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control |= request_private_bits << 4;
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pci_write_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
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control);
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set_irq_msi(irq, desc);
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write_msi_msg(irq, &msg);
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return 0;
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}
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/**
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* Called when a device no longer needs its MSI interrupts. All
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* MSI interrupts for the device are freed.
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*
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* @irq: The devices first irq number. There may be multple in sequence.
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*/
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void arch_teardown_msi_irq(unsigned int irq)
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{
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int number_irqs;
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uint64_t bitmask;
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if ((irq < OCTEON_IRQ_MSI_BIT0) || (irq > OCTEON_IRQ_MSI_BIT63))
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panic("arch_teardown_msi_irq: Attempted to teardown illegal "
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"MSI interrupt (%d)", irq);
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irq -= OCTEON_IRQ_MSI_BIT0;
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/*
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* Count the number of IRQs we need to free by looking at the
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* msi_multiple_irq_bitmask. Each bit set means that the next
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* IRQ is also owned by this device.
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*/
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number_irqs = 0;
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while ((irq+number_irqs < 64) &&
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(msi_multiple_irq_bitmask & (1ull << (irq + number_irqs))))
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number_irqs++;
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number_irqs++;
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/* Mask with one bit for each IRQ */
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bitmask = (1 << number_irqs) - 1;
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/* Shift the mask to the correct bit location */
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bitmask <<= irq;
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if ((msi_free_irq_bitmask & bitmask) != bitmask)
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panic("arch_teardown_msi_irq: Attempted to teardown MSI "
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"interrupt (%d) not in use", irq);
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/* Checks are done, update the in use bitmask */
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spin_lock(&msi_free_irq_bitmask_lock);
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msi_free_irq_bitmask &= ~bitmask;
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msi_multiple_irq_bitmask &= ~bitmask;
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spin_unlock(&msi_free_irq_bitmask_lock);
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}
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/*
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* Called by the interrupt handling code when an MSI interrupt
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* occurs.
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*/
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static irqreturn_t octeon_msi_interrupt(int cpl, void *dev_id)
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{
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uint64_t msi_bits;
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int irq;
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if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE)
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msi_bits = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_RCV0);
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else
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msi_bits = cvmx_read_csr(CVMX_NPI_NPI_MSI_RCV);
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irq = fls64(msi_bits);
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if (irq) {
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irq += OCTEON_IRQ_MSI_BIT0 - 1;
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if (irq_desc[irq].action) {
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do_IRQ(irq);
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return IRQ_HANDLED;
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} else {
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pr_err("Spurious MSI interrupt %d\n", irq);
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if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
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/* These chips have PCIe */
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cvmx_write_csr(CVMX_PEXP_NPEI_MSI_RCV0,
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1ull << (irq -
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OCTEON_IRQ_MSI_BIT0));
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} else {
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/* These chips have PCI */
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cvmx_write_csr(CVMX_NPI_NPI_MSI_RCV,
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1ull << (irq -
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OCTEON_IRQ_MSI_BIT0));
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}
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}
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}
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return IRQ_NONE;
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}
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/*
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* Initializes the MSI interrupt handling code
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*/
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int octeon_msi_initialize(void)
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{
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if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
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if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt,
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IRQF_SHARED,
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"MSI[0:63]", octeon_msi_interrupt))
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panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
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} else if (octeon_is_pci_host()) {
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if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt,
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IRQF_SHARED,
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"MSI[0:15]", octeon_msi_interrupt))
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panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
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if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt,
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IRQF_SHARED,
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"MSI[16:31]", octeon_msi_interrupt))
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panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
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if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt,
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IRQF_SHARED,
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"MSI[32:47]", octeon_msi_interrupt))
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panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
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if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt,
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IRQF_SHARED,
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"MSI[48:63]", octeon_msi_interrupt))
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panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
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}
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return 0;
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}
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subsys_initcall(octeon_msi_initialize);
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